Two helicopters of the British air force have crashed into the Gulf, after a mid-air collision.

A British military spokesman at coalition headquarters, Lt. Colonel Ronnie McCourt, said the two helicopters collided over international waters, shortly before dawn (4:30 a.m. local time) on Saturday. "Search and rescue operations are underway for the missing crewmen. We believe it was not the result of enemy action, and we will release details as soon as possible," he said.

It is the second helicopter accident in two days, as coalition forces advance into southern Iraq. A U.S. helicopter Friday crashed in northern Kuwait, killing four U.S. crewmembers and eight British soldiers.

Saturday's crash comes as coalition forces take the southern Iraqi port of Umm Qasr, and advance on neighboring Basra. It follows a night of intense coalition bombing of selected targets in Baghdad and other major Iraqi cities.